DE2848282A1 - METHOD AND DEVICE FOR THE PRODUCTION OF PERFORATED SHEET METALS - Google Patents

Description

Method and device for the production of perforated metal sheets

The invention relates to a method and a device for producing perforated metal sheets. Such sheets are in particular used for the automatic production of washing machine drums, the drum shell of which is known to be perforated Sheet metal.

If sheets are to be produced, which are perforated in a certain area over their entire width and in other areas are perforated only over part of their width, the conventional procedure is that all holes are simultaneously with a single punching tool, whereby in the areas in which no holes are to be created the The punching tool has no punch. This is, for example, for drum wall sheets for washing machines with loads the case from above.

In such a machine, the drum has an area of holes around its periphery, an area that of the access door for the drum, an area that corresponds to a flap door, and areas for attaching certain accessories which prohibit the perforation of the wall. The drum wall can be made from two pieces, which are folded over be connected, one of the pieces comprising the entrance door and the other comprising only the perforated area. For the production of the second piece, the holes must be punched in certain places across the entire width of the sheet metal while they are on in other places only over a limited area of the sheet metal in order to obtain the possibility of an inspection door to be able to attach.

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The known methods are hardly suitable for automation the production of the perforated drum sheets, since, in the event that different types of drum sheets are produced must be »it is necessary to move the very large and very heavy punching tools, which is time-consuming and difficult is.

The invention is based on the object of a method and a device for avoiding the aforementioned disadvantages To create production of perforated sheets, which are suitable for the production of perforated sheets with unperforated areas and which are characterized by great economic efficiency.

The solution to this problem is given in claims 1 and 2. Advantageous embodiments of the invention are Subject of the subclaims.

The invention is illustrated schematically in the following on the basis of the figures illustrated embodiment explained in more detail. It shows:

Fig. 1 is a perspective view of an apparatus for producing perforated metal sheets according to the invention

Fig. 2 shows the structure and mode of operation of the mechanism for sinking the punch and

Fig. 3 shows an example of a perforated sheet with a Device according to the invention was made.

In Fig. 1, a device for producing perforated metal sheets is shown in perspective, which according to the Invention is designed and in particular for the production of perforated metal sheets for the jackets of washing machine drums

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with loading from above is suitable.

The device is located under a press P of known type, which has a press ram which is vertically between two pillars moved. In the example considered, the press is part of a production chain for drum wall sheets, a unwinding device, a smoothing device, the hole punching device according to the invention, sheet metal shears and a "cleaning device", which is equipped with conical punches through which the edges of the punched holes are swaged back to achieve a completely smooth surface on the inside of the drum wall.

The device according to the invention consists mainly of three parts:

- A punch 1, which is equipped with a lowering mechanism for Punch is provided,

a feed device for large increments comprising a first clamping device 2. This consists of two parts connected to a one-piece slide, whereby this entire unit slides on guide rods driven by a piston between two adjustable stops, a feed ^{device 2} J for small increments with a second and a third clamping device 5, which on both sides of the punch 1 are arranged and equally consist of two parts connected to two one-piece sliding carriages 6, 7, which are mutually connected by a cross strut 8 and slide on guide rods 9. These two clamping devices are moved by a rack and pinion mechanism, the drive of which is synchronized with the downward movement of the press ram via a rod 10 which is connected to the drive device of the press.

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Before explaining the mode of operation of the device, the punching device is described in detail below. By the punching device must be transversal on the one hand in fully automatic production in one and the same sheet Rows of holes are generated in which the punch over the entire width of the sheet in action and on the other hand They have to create rows of holes in which certain areas remain unperforated and consequently the punch are sunk in the appropriate places. In Fig. 3, a drum wall plate is shown, the areas A and B in which no perforation holes need to be created. For the rows of holes, such as the row rl, all punches must be put into operation, while for the rows such as ra and rb by countersinking some punch the generation of holes must be partially suppressed. This problem is addressed according to the invention in solved in the following way:

the device has, for example, two complete rows of punching dies, through which two complete rows of holes can be created in the sheet metal. This device is located on the press table. The punch support part is actuated by the ram of the press, in which this is approximately in the Kind of a ram hits this, that means that the upper part of the tool, which carries the punch is not connected to the ram of the press. Rather, the ram hits the punch carrier during its downward movement, which are then only moved upwards by the action of springs.

A cam mechanism is used to countersink the punch in the rows of holes rA and rB, which cross areas A and B 12, 13 »14 provided, its structure and mode of operation schematically is explained with reference to FIG. This mechanism includes a first comb 12 on the ram of the press is attached over the punching device and the one between two

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Positions by an electromagneta-il ^, which is likewise with is connected to the plunger, is displaceable.

Opposite the first comb 12, a corresponding comb is provided on the punching device, which is on the punch carrier is attached and the length of which corresponds to the width of the area A or B, in which no holes are created should. The punches are shown in dashed lines in FIGS. 2a and 2b.

When the comb 12 is in the position shown in FIG. 2a and when the plunger is lowered, the protruding ones engage Parts of the comb 12 in the troughs of the lower comb 13, which is why the punch carrier is not actuated. If, on the other hand, the electromagnet is put into operation, so that the upper comb is in the position shown in FIG. 2b is moved, hit the protruding parts of the comb 12 against the protruding parts of the comb 13, whereby the Punches are actuated at the same time as the other punches in the row and, as a result, a row of holes, such as the series rl, is obtained.

With this device, sheets with complete perforation and with free areas can consequently in a simple manner be created. It is also within the scope of the invention to provide several combs by suitable means, such as For example, electromagnets are moved to perforated sheets with different geometric distributions.

As a result of the fact that in this lowering mechanism the Punch the control part and the actuation part are separate, the first on the plunger and the second on is attached to the punch, each time the press stops and consequently premature wear of the clutches and braking of the machine avoided. The operation of the

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Punch occurs between the end of the upward movement of the plunger and the beginning of closing.

The operation of the device will now be described.

The sheet metal, which comes from an unwinding device and has run over a smoothing device, arrives in the feed device 2, 3 with large increments in the direction of arrow T until it strikes the stop 15. The sheet will then taken by the clamping device 2, through which it is conveyed into the punching device 1, whereby it is through a suitable device (not shown) is centered. While the clamping device 2 is still closed the clamping devices 4 and 5 of the feed system with a smaller step, which is in the starting position for the punching process, also closed, so that the sheet is held taut in the punching device. It is therefore possible to make the holes in the sheet with large To attach accuracy. In such a device, in which the holes are punched in double rows, can the "cleaning process" can then be carried out for all punched holes with a single tool. For this it is necessary that the stamp for cleaning or smoothing the punched holes do not experience any shift in position relative to the punched holes. With the two feed devices according to the invention, it is possible to achieve a positional accuracy of the punched holes in the order of a tenth of a millimeter.

The punching device 1 continuously produces double rows in the sheet metal of punch holes, the comb mechanisms 12, 13, I ^ automatically controlled by the numerical control system of the production chain to create rows of punching in the sheet, some of which have no holes.

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After the end of the process, the clamping devices of the feed system are released for small increments and at the same time the clamping device of the feed system is closed for large increments. The feed device for large increments continues its movement and conveys the sheet metal under the sheet metal shears located at the exit of the press, with a new sheet metal being conveyed under the punching tool at the same time. The clamping devices h and 5 of the feed system for small increments are closed after the entirety of this system has been moved into the starting position with the aid of a piston. The punching cycle can then begin again.

It should be noted that the sheet metal is always clamped with the aid of the first or with the aid of the second and third clamping devices is, whereby the position of the punched holes is precisely determined.

Although an embodiment has been described, which relates to the production of perforated plates for drum walls of washing machines related, it goes without saying that with the method and the device according to the invention and perforated sheets can be created for other areas of application. The method and the device according to the invention are suitable for the production of perforated sheets which should not have any holes in some areas and in which the position of the holes is larger Accuracy should be specified.

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Claims (1)

PATENT LAWYERS DIETRICH LEWINSKY HEiNZ-OOACHIM KUAiX REiNGR PRiGTSCH 7. 11. 1978 M ONCH-E N 2 1 10.696-V / Th GOTTHARDSTR. 81 THOMSON-BRANDT 173, Bl. Haussmann, 75008 Paris (France) Claims (1 ^ method for producing perforated plates, characterized in that - That the sheet metal from a first clamping device (2), which is part of a feed device (3) for large Increment is, is taken and unwound from a roll to feed it to a punch, that after automatic centering of the sheet with respect to the punch, the sheet between a second and a third clamping device (4, 5) is held taut, the parts of a feed device (6, 7) are for small increments and lie on both sides of the punching area, with the first Clamping device (2) is released and the hole punching in rows with the help of the feed device (6, 7) for small increments with automatic lowering of the punch in areas of the sheet metal without holes takes place, and that after completion of the punching the first clamping device (2) closed and the second and third Clamping device (4, 5) are opened and the punched sheet metal through the feed device (3) with large step size promoted to a tin snips 909819/0931 and a new untreated sheet is introduced into the apparatus. Device for the production of perforated sheets characterized by a punch with transverse punches that open on are attached to the table of a press and a mechanism (12, 13) 14) for lowering the punch for show the case of the creation of hole-free sheet metal areas, - A feed device (3) for large steps with a first clamping device (2) to the sheet to convey into the punch and remove from it and - A feed device (6, 7) for small increments with a second and a third clamping device (4, 5), by means of which the sheet metal is kept taut on both sides of the punching area and during the punching of the holes is moved forward step by step. Device according to Claim 2, characterized in that the clamping devices (2, 4, 5) of the feed devices (3, 6, 7) for large and small increments can be controlled so that the sheet is always through the first clamping device (2) is clamped on the one hand or by the second and third clamping devices (4, 5) on the other hand, to ensure the precision of the hole punching. Device according to claim 2, characterized in that the mechanism for lowering the punch has a first, movably attached to the ram of the press with the aid of an electromagnet likewise attached to the ram (14) displaceable first comb (12) and a second one connected to the punch holder of the device Comb (13) comprises, the first comb (12) through the 9 0 9 "1 η / fi '? 3 1 Electromagnet (I ¹ I) is moved so that it has a
Active position (b), in which holes are punched and the projections of the first comb (12) come into contact with the projections of the second comb (13), and assumes a passive position (a) in which no holes are punched and the projections in the recesses of the second comb (3) engage when the ram of the press moves downwards. -H-